- 新建一个空工程
- 新建一个maven模块
- 在pom.xml中添加
<parent>
<artifactId>spring-boot-starter-parent</artifactId>
<groupId>org.springframework.boot</groupId>
<version>2.7.5</version>
</parent>
- 在pom.xml中添加依赖
<dependencies>
<!--spring-boot-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--lombok依赖，实现数据get/set-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<!--mybatis依赖-->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.2.2</version>
</dependency>
<!--mysql依赖-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
</dependencies>
- 在main\java中新建package：com.cxsbg
- 在resources中新建application.yml定义相关的配置
#服务端口
server:
port: 80
#mysql配置
spring:
datasource:
url: jdbc:mysql://localhost:3306/db_test?characterEncoding=utf-8&serverTimezone=UTC
username: root
password:
driver-class-name: com.mysql.cj.jdbc.Driver
#mybatis配置
mybatis:
mapper-locations: classpath:mapper/*Mapper.xml #mapper路径
type-aliases-package: com.cxsbg.domain #bean路径
- 在cxsbg下新建启动类WebApplication
package com.cxsbg;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class WebApplication {
public static void main(String[] args) {
SpringApplication.run(WebApplication.class,args);
}
}
- 在cxsbg下新建controller包，在controller包中新建controller类
package com.cxsbg.controller;
import com.cxsbg.domain.ResponseResult;
import com.cxsbg.domain.User;
import com.cxsbg.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController //controller注入
@RequestMapping("/user") //路由地址
//@CrossOrigin //支持跨域
public class UserController {
@Autowired //获得相应的service
private UserService userService;
@RequestMapping("/findAll")//路由地址
//统一返回数据格式ResponseResult
public ResponseResult findAll(){
//调用相应的service函数，获得查询数据
List<User> users = userService.findAll();
//返回统一数据格式
return new ResponseResult(200,users);
}
}
- 在cxsbg下新建domain包，在domain包下新建统一返回数据类ResponseResult和实体类（如User类）
package com.cxsbg.domain;
import com.fasterxml.jackson.annotation.JsonInclude;
@JsonInclude(JsonInclude.Include.NON_NULL)
public class ResponseResult <T>{
//状态码
private Integer code;
//提示信息
private String msg;
//结果数据
private T data;
public ResponseResult(Integer code, String msg) {
this.code = code;
this.msg = msg;
}
public ResponseResult(Integer code, T data) {
this.code = code;
this.data = data;
}
public ResponseResult(Integer code, String msg, T data) {
this.code = code;
this.msg = msg;
this.data = data;
}
public Integer getCode() {
return code;
}
public void setCode(Integer code) {
this.code = code;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
}
package com.cxsbg.domain;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data //lombok实现get/set
@NoArgsConstructor//lombok
@AllArgsConstructor//lombok
public class User {
private Integer id;
private String name;
private Integer age;
}
- 在cxsbg包下新建service包，在service包中新建对应的接口（如UserService），在service包下新建impl包来实现接口，在impl包下新建接口实现类（如UserServiceImpl）
package com.cxsbg.service;
import com.cxsbg.domain.User;
import java.util.List;
//定义一个接口类
public interface UserService {
List<User> findAll();//相应的函数接口
}
import org.springframework.stereotype.Service;
import java.util.List;
//实现接口
@Service //Service注入
public class UserServiceImpl implements UserService {
//用mapper操作数据库实现
@Autowired //引入对应的mapper，实现底层数据库操作
private UserMapper userMapper;
@Override
public List<User> findAll() {
return userMapper.findAll();
}
}
- 在cxsbg包下新建mapper包来存放对应的mapper，在mapper包中建立接口，定义对应的接口函数
package com.cxsbg.mapper;
import com.cxsbg.domain.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper //mapper注入
@Repository //bean注入
public interface UserMapper {
List<User> findAll();
}
- 根据配置文件中的路径，在resources下新建mapper包，在mapper包中新建对应的xml，实现mapper接口中的函数
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.cxsbg.mapper.UserMapper">
<select id="findAll" resultType="com.cxsbg.domain.User">
select * from user
</select>
</mapper>
- 配置跨域，在cxsbg包下新建config包，在config包中新建CorsConfig类
package com.cxsbg.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration //注入配置
//实现WebMvcConfigurer接口
public class CorsConfig implements WebMvcConfigurer {
@Override
public void addCorsMappings(CorsRegistry registry){
//设置允许跨域的路径
registry.addMapping("/**")
//允许跨域请求的域名
//.allowedOrigins("*")
.allowedOriginPatterns("*")
//是否允许cookie
.allowCredentials(true)
//允许的请求方式
.allowedMethods("GET","POST","DELETE","PUT")
//允许的header属性
.allowedHeaders("*")
//跨域允许时间，第一次允许之后3600秒内都不会再次向服务器询问是否允许跨域
.maxAge(3600);
}
}
- 启动WebApplication
